Method of dressing piston-rings and apparatus therefor.



W. T. CLARK. METHOD or DRESSING PISTON RINGS AND APPARATUS THEREFOR.

APPLICATION FILED AUG- IGI I909. I

Pahmted Mar. 20, l9l7.

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wwnmmm W. T. CLARK. METHOD OF omssmqmsrou muss AND APPARATUS THIIREFORI.

APPLICATION FILED AUG, I6, I909- 1,21 9,440. Patented Mar. '20, 1917.

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, wmm Wide WZYZdc/F WILLIAM T. CLARK, OF BELOIT, WISCONSIN.

METHOD OF DRESSING PISTON-RINGS AND APPA] tA'IUS THEREFOR.

Specification of Letters Patent.

Patented Mar. 20, 1917.

Application filed August 16, 1909. Serial No. 513,177.

To all whom it may concern Be it known that I, VVILLIAM T. CLARK, a citizen of the United States, residing at Beloit, in the county of Rock and State of Wisconsin, have invented certain new and useful Improvements in Methods of Dress ing Piston-Rings and Apparatus Therefor, of which the following is a specification.

In dressing piston rings, it has been the custom, so far as I am aware, to completely prepare them before applying them to the pistons, and consequently even if rings are perfectly true, they are apt to be distorted when they are placed in position on a piston, so that they are misshapen when in position.

The primary object of the present inven tion is to provide a simple and comparatively inexpensive apparatus, which will properly dress and true piston rings after the have been applied to a piston, so that their accuracy of form is absolutely assured.

A further object is to provide an apparatus of this character, that is in the form of an attachment to an ordinary lathe, and can be readily applied to such lathe by any mechanic.

The preferred form of construction is illustrated in the accompanying drawings,

Figure 1 is a top plan view of the apparatus.

Fig. 2 is a side elevation of the same.

Fig. 3 is an end view.

Fig. 4 is a vertical sectional view on the line H of Fig. 2.

Similar reference numerals designate corresponding parts in all the figures of the drawings.

In the embodiment illustrated, a support is employed, in the form of a frame 5 which may be secured to the movable carriage 6 of a lathe, which slides on the supporting tracks or guides, 7, of an ordinary latheframe. A base, 8, mounted on the frame 5, supports a cylindrical guide, 9, that is openended and is arranged to rotatably receive a piston, which piston is designated 10. This piston-receiving guide is of the same internal diameter as that of the cylinder in which the piston is to be used and is provided in one side with one or more vertical slots, 11, three being shown in the present instance.

The frame 5, on the side of the guide, 9, having the slots, has mounted thereon, a block 9, which is provided with guideways,

12, transverse to the lathe guides 7, that receive the base, 1.3, of a supporting carriage, slidable toward and from said guide. The carriage is opei'ated by an adjusting screw, 1%, engaged with said carriage and with the frame, and hav .ng an operating hand wheel, 15. The carriage has a pair of standards, 16, terminating at ",heir upper ends in boxes,17, in which is journaled a shaft, 18, carrying a grinding or ab rasive wheel, 19, the periphcry of which 01: crates in any of the slots, 11. The shaft, 18, may be driven by any suitable means, as for instance, a belt, from some source of power that operates upon a pulley, 20, fixed to the shaft between the boxes, 17.

The position of the wheel may be altered by shifting the block, 9 along the frame 5, longitudinally, of the cylindrical guide, and said block is held by bolts, 21, the heads of which are slidzbly engaged in the slot 22 of the frame 5.

In order to r( ceive and remove dust, chips, and the like f1 cm the cylindrical guide, a suitably supported hood 22 is located over the slot'and gr: nding wheel, this hood having a discharge outlet 23, to which may be coupled an exhaust pipe.

The operation of this apparatus is as follows: The rings to be dressed are first sprung into the ring grooves of the piston 10 and are then placed with the piston within the cylindrical guide 9 with the rings pressing against the interior surface thereof. As the internal diameter of the cylindrical guide is the same as that of the cylinder in which the piston and rings are to be used and as the rings are cut or split to have a tendency to spring outward, the rings are pressed by the guide into their proper circumferential P)Sltl0l1. The piston is then connected by a suitable shaft 24 to the lathe spindle so that it and the rings may be rotated. The rings are usually connected to the piston y dowel pins. The carriage which supports the grinding wheel is then moved inward to bring the wheel into contact with the ring through one of the slots 11 and the lathe carriage is moved longitudinally back and forth while the ring is being thus acted upon. The longitudinal movement of the lathe carriage may be sufficient to bring the grinding wheel into contact with all of the rings upon the piston or, if desired, one of them may be dressed and the carriage then moved into position to grind another ring,

and so on. The .lrawing shows a plurality oi slots 1.1. These and the longitudinal adjustment of the block 9 are provided so that if after the a maratus has been in use for any considerable length of time that portion of it opposite one of the slots becomes worn and out of true, the grinding wheel may be shifted. to a position opposite another of the slots so that the life of the apparatus is largely increased.

The result is that the rings are finished on their own pistons in accurate and correct shape, capable of fitting their cylinders perfectly, that is, the rings are the same as they would be if they could be and were ground in the cylinders in which they are to be used.

It will be obvious that this structure is exceedingly simple and that it may be in the form of an attachment to an ordinary lathe. Furthermrn'e it will be clear that instead of a. grinding wheel, a machine tool may be employed for effecting the dressing operation.

From the foregoing, it. is thought that the construction, operation and many advantages of the herein described invention will be apparent to those skilled in the art, without further description, and it will be understood that various changes in the size, shape, proportion and minor details of construction, may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In an apparatus for dressing piston rings on their pistons, a cylindrical gage constructed with an opening through its side, said gage being adapted to receive a piston with a split piston ring of resilient material thereon and arranged to compress said ring to the diameter of the cylinder in which it is to be used, an adjustable dressing device arranged to operate upon the ring through said opening, means for rotating the piston and its ring within the gage, the piston and the dressing device being arranged 'lor relati ve movement.

2. In an apparatus for dressing piston rings on their pistons, a cylindrical gage constructed with a short transverse slot through its side, said gage being adapted to receive a piston with a split piston ring of resilient material thereon and to compress said ring, a grinding wheel arranged to operate upon the ring through said slot while said ring is compressed by the gage to the diameter of the cylinder in which .it and the piston are to be used and while the ring is held normal to the axis of the gage, means for rotating the piston and its ring within the gage, the piston and the grinding wheel being arranged for relative longitudinal movement.

3. A. lathe attachment for grindii'ig piston rings on their pistons iii1 l'isiiig a frame adapted to be secured to the longitiuliaall movable lathe carriage, a cylindrical "age aflixed to said frame constructed with a short transverse slot through its side, said gage being adapted to receive a piston with a split ring of resilient material thereon and to compress said ring, a transverse guide on said frame opposite the slot in the gage, a grinding wheel adjustably mounted upon said guide, and means for connecting the piston within the gage with the spindle of the lathe to be driven thereby.

4. The herein described method of dressing piston rings which comprises placing the rings upon the pistons upon which they are to be used, compressing said rings to the diameter of the cylinder in which they are to be used, and grinding them while thus compressed.

In testimony whereof I hereunto affix my signature in the presence of two witnesses.

WILLIAM T. CLARK.

Witnesses:

MARY C. WHELAN, T. D. VVooLsEY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patenzs, Washington, D. 0. 

